Startup Dependencies with Python

[abhi-arya1]

How would I go about adding a startup function (a Python script to be exact) that runs when the app is launched? I've added a function to main.ts in src to do this (below), but it hasn't responded and just runs the createWindow() function. The only time it worked was when I added the python3 [path to script] to npm start but this doesn't worked when the app is packaged. I have not edited anything further than main.ts besides the npm start script in package.json above (which was removed)
Any help would be appreciated as the Python script is a tkinter module that populates a necessary json file. Additionally, this has to be a cross-platform application, so I can't use Pyinstaller to create .exe files.
Thanks!

app.whenReady()
    .then(() => {
        runPythonScript(); // does this via the execSync() method from 'child-process'
        createWindow();
        app.on('activate', () => {
            if (mainWindow === null) createWindow();
        });
    })
    .catch(console.log);

My python script at the moment for testing is just this:

import tkinter

if __name__ == "__main__":
    window = tkinter.Tk()
    window.mainloop()